1) When people tell me/remind me to do stuff that I already know or plan to do --E.g., don't forget to send me this; be sure to mail this, etc. Yes, I know people are just trying to be helpful, and granted, I do need reminders from time to time. But still, it's a bit annoying because I don't like repetition.
2) Cheerful people in the morning and cheerful people on Monday mornings asking what you did last weekend --Yes, I know they are just trying to be nice, but I'm not a morning person and I hate the whole chit-chat thing in morning because it's just so contrived. Tne you feel you have to ask about them and their morning too. Not that I'm not interested in your life, because I am, but please, at least let me have my coffee first! Alas, I know it's part of the daily work routine and I will never escape it.
3) People who are picky with their food. Yes, I know some folks can't help it. And no, this is not aimed at vegetarians, vegans, etc. This is for people who just don't want to venture out and refuse to eat anything they haven't eaten before; or for people who hate certain food but haven't even tried it. Or for people who think that fish served with the head (as opposed to a fillet) is "exotic". Please.
4) Slow-loading web-pages.
5) People who don't send proper thank you cards. Did you grow up without manners or what? No, I'm not talking about your daily gift-exchange (e.g., giving your friend a b-day gift or whatnot). This is about people who make the effort to do something nice for you like letting you stay at their house; people who send you a gift even though you are far away; people who took the time to do something for you. I admit, I'm guilty of this too. I've received presents from people and never formally thanked them. But for the most part, I do try to be polite and send a nice note in the mail.
Well, that's just some things.